hard disk Last modified: Tuesday, March 11, 2003
A magnetic disk on which you can store computer data. The term hard is used to distinguish it from a soft, or floppy, disk. Hard disks hold more data and are faster than floppy disks. A hard disk, for example, can store anywhere from 10 to more than 100 gigabytes, whereas most floppies have a maximum storage capacity of 1.4 megabytes. A single hard disk usually consists of several platters. Each platter requires two read/write heads, one for each side. All the read/write heads are attached to a single access arm so that they cannot move independently. Each platter has the same number of tracks, and a track location that cuts across all platters is called a cylinder. For example, a typical 84 megabyte hard disk for a PC might have two platters (four sides) and 1,053 cylinders. In general, hard disks are less portable than floppies, although it is possible to buy removable hard disks. Also see What's Inside a Hard Drive? in the Did You Know . . . ? section of Webopedia.
•E-mail this definition to a colleague• Sponsored listings Hard Drives - Customize Hard Drives with your company logo. Guaranteed low prices and great service. Shop online. Hard Drives - Complete line of adapters - from software RAID to SAS/SATA hardware RAID. Learn more, access podcasts of industry experts on data storage technology. GlobalSpec.com: Computer Hard Drives - Provides database of suppliers for Computer Hard Drives. Browse catalogs and view technical information. For internet.com pages about hard disk . Also check out the following links! Hard Disk Logical Structures and File Systems  Describes "standard" file systems used on PCs, with particular focus on the FAT file system and its variants. This page is from "The PC Guide." PC Guide's hard disk drive reference  Offers a large amount of information covering construction and operation, geometry and formatting, performance factors, BIOS and size issues, interfaces, configuration and file systems. Disk Manager product page Describes Ontrack Computer's Disk Manager product, a hard disk installation package. Hard Disk BIOS and Capacity Factors Describes issues related to how the BIOS and operating system interact with the hard disk, and BIOS-related issues and problems. Includes a full look at the many capacity limitations inherent in using IDE/ATA interface drives, and other BIOS restrictions on hard disk capacity. This page is from "The PC Guide." Hard Disk BIOS Translation Modes Detailed description of the various types of BIOS translation that are used in modern PCs. Includes sections on normal/standard CHS mode, Extended CHS/large mode, Logical Block Addressing (LBA), a comparison of translation modes, and caveats on changing translation modes and transferring hard disks between PCs. This page is from "The PC Guide." Hard disk information page This site hosts a collection of information on hard disks, including an EIDE FAQ, the bus master DMA features and drivers and troubleshooting, driver information, and manufacturer pages. Sponsored listings Hard Drives at Dell Business - Shop for Hard Drives and Accessories for your Small Business. Buy Dell Direct & Save. Find Computer Hard Disk Factory at TDC Online Sourcing - Find the best computer hard disk factory from China, Hong Kong and Taiwan at the award-winning TDC online Marketplace. Data Recovery Software - Find Hard Disk Recovery Utilities Solutions and Compare prices at Shopica.com. Search products and stores before making a purchase. Start Now! Computer Forensics Education & Training - Computer Forensics Education & Training offered online by accredited colleges. Request more info today. IBM Hard Disk Drives - A full service provider of IBM RS/6000 and pSeries servers, disk drives, workstations, and parts. Offers vast inventory, testing and refurbishment.	Hard Disk Drives cache cylinder disk drive disk pack EIDE floppy disk ghost imaging hard card hard disk type HLF IDE interface interleave LLF mass storage platter removable hard disk ScanDisk SMART track Give Us Your Feedback Hard Drives hard disk Products Shop by Top Models: Western Digital My Book Essential 500GB External USB 2.0 - WDH1U5000N 500 GB Hard Drive 18 store offers from $100 - $187 Seagate FreeAgent™ ST901603FGA1E1-RK 160 GB USB 2.0 Hard Drive 11 store offers from $88 - $149 Seagate FreeAgent™ (ST305004FDA1E1-RK) 500 GB USB 2.0 Hard Drive 18 store offers from $100 - $170 Western Digital My Book™ Essential Edition 2.0 (1000 GB) 1 TB USB Hard Drive 20 store offers from $200 - $280 Western Digital Passport™ WDXMS2500TN 250 GB USB 2.0 Hard Drive 3 store offers from $123 - $200